Slitherlink: one loop, no loose ends

Slitherlink is now part of TAPA GAME's puzzle selection. Draw one closed loop along the dotted grid. A number inside a cell tells you how many of its four surrounding edges belong to the loop. The finished line cannot branch, cross itself or split into several separate loops.

Start with a number you can settle

A 0 excludes all four edges around its cell. Mark those edges as unavailable so they stop competing for your attention. A 3 needs three of its four edges, so a neighboring exclusion can force the remaining lines.

At each grid point, a line has to continue as part of the loop. A loose end needs another connected edge; a junction with three selected edges would branch. Use that local rule alongside the numbered cells.

Do not close a loop too soon

A small loop can satisfy several clues and still leave unfinished numbers elsewhere. Closing it would isolate the rest of the board because the solution must be one loop.

Before adding the closing edge, look for other selected lines and unsatisfied clues. They need to belong to the same final route. The global rule is just as important as getting an individual cell's count right.

Mark what you know

Tap an edge to cycle through a line, a cross and a clear edge. Crosses record exclusions; they are useful information rather than decoration. Keyboard play uses arrows and Enter, with U for undo and R for retry.

There are twenty levels. Begin with definite exclusions, then extend lines where only one continuation remains. Keeping those marks visible makes it easier to return to a partially solved area without repeating the same deductions.